FOOD AND ITS RELATION TO HEALTH 239 



spring diet is shown in figure 19. Unexpected is the high yield of the sumach fruits, con- 

 sidered by many to be "starvation food". The leaves of some wood ferns contain even 

 higher amounts. 



Crude fiber 



Under this heading are placed the indigestible carbohydrates, such as cellulose, lignin and 

 chilin, as well as the resins and tars that are not soluble in ether. As such they probably are 

 the least useful items in the picture. Unfortunately it is not known to just what extent 

 grouse can digest this material. Most mammals can obtain little of value as food from it. 

 although ruminents, such as cattle and deer, are able to extract therefrom some nourishment 

 with the aid of certain bacteria. 



As might be expected, such winter and spring foods as buds, twigs and evergreen leaves 

 all contain large quantities of crude fiber. A notable exception to this is the buds of cherry, 

 which interestingly enough are taken more extensively in New York than is any other win- 

 ter food. Apple buds and sumach fruits are also fairly low in fiber content. Here is a 

 problem much in need of further study. 



Ash 



Under the heading ash is included the total measurable mineral matter that these plants 

 contain. Since animal life is ultimately dependent upon vegetation for the majority of the 

 inorganic portion of its make-up, the ash constituents, which provide the calcium, phos- 

 phorus, manganese and other body needs, become highly important. Buds of apples, blades 

 of certain grasses and fronds of wood ferns, all commonly taken spring foods, are excep- 

 tionally high in mineral content. This is in fact characteristic of most grouse foods taken in 

 late winter and early spring. The need for two of these minerals is indicated in that the cal- 

 cium requirement for domestic chicks is 0.7 per cent; that of phosphorus 0.5 per cent; for 

 laying hens it is 2 per cent and 0.8 per cent, respectively. Assuming grouse needs to be some- 

 what comparable, those requirements are probably satisfactorily met at least in the spring diet. 



An element less prominent but exlremely important is manganese. Norris' experiments 

 showed it to play a large part in the prevention of perosis or slipped tendon^"". This was 

 formerly a connnon ailment of game birds raised in captivity, as well as in domestic fowl. 

 It is described in somewhat greater detail in the chapter on Parasitism and Disease. 



The character of the soil strongly influences the mineral content of a plant. Wide varia- 

 tions in the ash constituents of a species in different portions of its range are therefore to be 

 expected. Aspen buds gathered near Ithaca, N. Y., contained half again as much mineral 

 matters as did those analyzed by Hellmers'*", taken a little over a hundred miles south, in 

 Pennsylvania. 



Vitamins 



In any discussion of nutrition the role of vitamins must play an important part. The 

 artificial rations fed to captivity-raised grouse at the Center are, of course, fortified to insure 

 the presence of these elusive substances in sufficient quantity, but their status in the normal 

 diet is at present little understood. Nor is there much known of the basic amounts required 

 for proper groulh and reproduction. The curing of a paralysis in grouse on experimental 

 feeds by the use of vitamin B extract may mean that the chicks have an unusually high vita- 

 min B requirement. Studies by Norris indicated the need of young pheasants for vitamin D 



